1. Field of the Invention
The invention relates generally to devices and methods for removing water from a subterranean wellbore.
2. Description of the Related Art
The presence of water is natural gas wells is a significant hindrance to the production of gas. Water naturally migrates into a wellbore along with the natural gas. In the beginning of production, the gas flow rate is high enough that it carries the water to surface. As the well matures, the flow rate begins to drop. Eventually, water collects in the wellbore to the point where the production rate becomes very low. In some cases, the weight of the water increases pressure within the wellbore and prevents gas in the surrounding formation from entering the wellbore.
In the past, gas lift valves have been used to help lift the water out of the well. In these instances, a gas (such as compressed air) is injected into the gas lift valve from the surface to try to lift the water out of the well. This approach is problematic in that it is expensive and requires large supplies of compressed gases to maintain an acceptable flow rate of production from the well.
Prior art approaches to the removal of water from a natural gas well are discussed in U.S. Pat. Nos. 5,211,242; 5,501,279 and 6,629,566.